Lubricating compositions



ire States This invention relates to improved lubricating oil compositions and to a new class of additives therefor.

Rigorous requirements have been set up to quality control lubricating oil composition for use in particular type of services. This is particularly true for gear oils which must meet gear test requirements such as the L-37 and L-42 gear tests and Ordnance 325 F. Thermal Stability test. To meet these and other requirements the oil compositions must be stable over a Wide temperature range and possess excellent antiwear and extreme pressure properties as well as resistance to oxidation, corrosion and be resistant to contamination by foreign matter.

Now, in accordance with the present invention, a new additive has been found which imparts excellent properties to such lubricants so that they satisfactorily meet the above requirements.

The new additive is an alkali metal-amine halohydro carbyl phosphonate and this additive, although it can be used per se as an oil additive, is particularly compatible with certain oil-soluble sulfur or sulfur-chlorine-containing organic extreme pressure agents and oil-soluble partial esters of polyhydric alcohols and organic carboxylic acids, and the combination produces unexpected and improved results.

The new alkali-meta1-amine halohydrocarbyl phosphonate has the general formula:

X XM Ri (XH)-A (I) wherein R is a halohydrocarbyl, preferably a middle halogen (C1 or Br) hydrocarbyl such as chloro and/or bromoalkyl, chloro and/ or bromocycloalkyl, chloro and/ or bromoaralkyl or chloro and/ or bromoalkaryl radicals having from 1 to 30 and preferably 1 to carbon atoms, X is selected from the group of oxygen and sulfur, M is an alkali metal, e.g., Na or K and A is an amine, preferably a primary or secondary aliphatic amine which may be straight or branch-chain, preferably the latter. A pre ferred class of compounds represented by Formula I may be represented by the formula:

wherein R represents a middle halogen atom, e.g., Cl or Br, 21 hydrogen atom or an alkyl group, the total number of carbon atoms in the alkyl group represented by R being 3, R may be the same as R or a hydrocarbyl radical of up to carbon atoms, preferably when R is not hydrogen or a middle halogen atom, it is an alkyl radical of 2 to 18 carbon atoms, and A represents a higher highly branched aliphatic primary or secondary amine, preferably a C highly branched aliphatic primary amine.

The acid portion used to make the mixed metal-amine salts can be prepared by a number of suitable methods such as reported by Arbuzov (Jr. Gen. Chem. USSR; 4,898-900 (1934); Coover (Organic Chemical Bulletin, vol. 23, No. 4, 1951), Barnard (Can. Jr. of Chem, vol. 31, pp. 976983, 1953). Suitable chlorohydrocarbylphosphonic acids for preparing the new alkali metalamine salts include monochloromethylphosphonic acid, 1-monochloroethylphosphonic acid, l-monochloropropylatent phosphonic acid, 1-chloro-l-rnethyl-ethylphosphonic acid, 1-cl11oro2-methy1-propylphosphonic acid, l-chlorobutylphosphonic acid, 1-chloro 1 methyl propylphosphonic acid, trichloromethanephosphinic acid, trichloromethanethiophosphinic vacid, 1,1-dib-romoethanephosphinic acid, 3,3,5-trichlorocyc1ohexanephosphinic acid, 1,1-dich1orohexadecanephosphinic acid, 1,1-dichlorohexadecanephosphinic acid, trichloromethanephosphinic acid, 1,1-dichloroethanephosphinic acid, 2,2,2-trichloroethanephosphinic acid, tribromomethanephosphonic acid, dichloromonobromornethanephosphonic acid, 1,1-dibromobutanephosphonic acid, 1,1-dichlorophenylethanephosphonic acid, 3,3,5-trichlorocyclohexanephosphonic acid, 3,5-dichlorocyclohexanephosphonic acid, 1,1-dichloropropanephosphonic acid, 3,3,3-tribromopropanephosphonic acid, 1,1- dichloroethanephosphonic acid, 1,1-dichlorobutanephosphonic acid, dichlorophenyl benzenephosphonic acid, 1,1-dichloro-2-monobromobutanephosphonic acid, 1,1-dichlorooctanephosphonic acid, trichloromethanethiophosphonic acid, 1,1-dibromobutanethiophosphonic acid, 3,3,5 trichlorocyclohexanethiophosphonic acid, 1,2 dichloroethanet-hiophosphonic acid, trichloromethaneselenophosphonic acid and the like.

The amines which can be used to form salts of the above phosphorus acids include highly branched primary aliphatic amines or secondary aliphatic amines of at least 8 carbon atoms. Of the highly branched primary aliphatic amines, the tertiary alkyl primary amines are preferred and they can be prepared by any suitable means such as described in the US. Ofice of the Publication Board Report No. 88,843. Other highly branched primary amines can be prepared by converting primary branched chain alcohols as produced by the Oxo process from branched chain olefins as fully described by P. W. Sherwood in the Oil and Gas Journal, June 9, 1949, page 71, and in the February 1953 issue of Petroleum Processing, to the corresponding nitriles and converting the nitrile to the amine by catalytic hydrogenation. Another method is to convert alcohols to the corresponding halides and to form the amines derived from the halide in the customary manners such as by reacting with ammonia.

It has been found that the tertiary alkyl primary amines, containing, as the tertiary alkyl radical, the radical of polyisobutylene, polypropylene and mixture thereof are particularly efiective for the present purpose and they constitute a preferred class of amines for the practice of the invention. Accordingly, 1,1,3,3-tetramethylbutylamine (from the amination of diisobutylene), 1,1,3,3,5,5- hexamethylhexylamine (from triisobutylene), 1,1,3,3, 5,5,7,'7-octamethyloctylamine (from tetraisobutylene) and 1,1,3,3,5,S,7,7,9,9-decamethyidecylamine (from pentaisobutylene) are specific preferred amines, which are suitably used individually or as mixtures thereof. In addition to these tertiary alkyl primary amines, primary tertiaryalkylmethylamines, such as 2,2,4,4-tetramethyl pentylamine, 2,2,4,4,6,6-hexamethyl heptylamine and the like are suitable.

Other tertiary branched-chain alkyl primary amines which can be used include the C and higher amines of this type mentioned in US. Patents 2,160,058, 2,606,923 and 2,611,782, such as tert.-tridecylamine 12115 as well as isoheptyldiethylcarbinyl amine, isooctylethylpropylcarbinylamine, and the like. Primary amines of this type are commercially available from Rohm and Haas Company under the trade name of Prirnenes, specific products being Primenes 81R, which is a mixture of primary alkylamines containing from about 12 to 15 carbon atoms and Primene JMT, which is a similar tertiary alkylamine mixture containing an average of about 18 to 24 carbon atoms.

The following are the properties of some amines which can be used to form the amine salts.

T able 1 .-Properties 'lertiary-Oetylarnine Alkylamine SI-R A1 Allrylamine JM-T A l'rCaHnNHs "I Formula Principally t-CuH25 Principally t-CmH 31 NH: 120 t-C'uHa Nllz Nl'lc t0 t'CZlIi-MNIIL Molecular Weight 129 Principally 1712l3 Principally 269-353. Average Molecular Weight we 1m 301. Specific Gravity, 25O 0.771 O. 81? 0.828. Refractive Index, 25C 1, 423 1. 423 1. 455. Boiling Point (or range) 137143 C. (760 mm.) 590% at 210-227 G. 595% at 275-310 C.

760 mm.). (785 mm.

The secondary amines which can be used to form salts of the phosphorus acids include secondary amines, preferably aliphatic and cycloaliphatic amines, containing from to 36 carbon atoms. Illustrative of such amines are diamlyamine, dihexylamine, di(2-ethyl-hexyl) amine, dioctylamine, didecylamine, ditetradecylamine, dihexadecylamine, dioctadecylamine, didodecylamine, dibromodioctadecylamine, isopropyloleylamine, diricinoleylamine, butylricinoleylamine, butyl-2-ethylhexylamine, dilaurylamine, methyloleylamine, ethyloctylamine, isoamylhexylamine, dicyclohexylamine, dicyclopentylamine, cyclohexyloctylamine, cyclohexylbenzylamine, benzyloctylamine, benzyl-Z-ethylhexylamine, allyloctylamine, dodecyl-2-ethylhexylamine, l-isobu tyl-3 -methylbutyl -3 ,3 S-methylcyclohexylamine, di(1-isobutyl-3-methylbutyl) amine, N-n-dodecyldiethylenetriamine, N-n-tetradecyldiethylenet'riamine, octylethylene diamine, N-Z-ethylhexyl N-hexadecyl triethylene tetramine, heptyl trimethylene diamine, N-tetradecyl tripropylene tetramine, N,N'-diallyl trimethylene diamine, 3-hexyl-morpholine, and the like.

The method of making the mixed alkali metal-amine salts is to first prepare the full amine salt by the methods described in US. Patents 2,777,819, 2,858,332, 2,874,120 or 2,882,228 and thereafter treat the full amine salt in a low boiling solvent such as methanol with an alkali metal such as sodium, potassium or lithium hydroxide, carbonate, alcoholate, e.g. methylate, in an amount sufficient to replace one of the amine groups with an alkali metal. The mixture is warmed while stirring and when the reaction is complete the temperature is increased to boil off the solvent, e.g. methanol, and it may he neces sary to strip the product with nitrogen to remove last traces of the solvent. An alternative method of preparing the alkali metal-amine salts such as sodium-amine phosphonate is to dissolve sodium in methanol and add the sodium methylate dropwise while stirring to a full amine salt of an alkyl phosphonic acid at 100200 C. for /2 to 10 hours. The methanol is removed by nitrogen stripping to give a new sodium-amine phosphonate.

For example (I), 0.5 gram of sodium was dissolved in ml. of methanol and this was added dropwise with stirring to C primary alkylamine (mixture of A of Table 1) salt of monochloromethylphosphonic acid. The :addition was carried out at 165 F. and required about 20 minutes after which the mixture was held at this temperature for minutes. The methanol was removed with nitrogen stripping to give a clear product containing 0.11% wt. sodium.

Example II was prepared in accordance with the procedure of Example I, except that A amine salt of trichloromethylphosphonic acid was used. The final product Na-A amine trichloromethylphosphonate was oil soluble and possessed good extreme pressure properties.

Other examples of alkali metal-amine salts of this invention include mixed salts of Na or K with from primary amines such as t-C H NH t-C H NH to 15 31 1, t-C18H37NH to c,,H,,NH,, dimethyl neopentylcarbinyl amine, tert.tridecylamine, or with secndary amines, e.g., di-Z-ethylhexylamine, di-l-isobutyl- 3-methylbutylamine, didecylamine, dioctadccylamine, isomethanephosphonic acid, trifluoromethancphosphonic acid, tribromomethanephosphonic acid, trichloromethanedithiophosphonic acid, chlorobenzene trichloroinethancphosphinic acid, 1,l-dichloroethanethiophosphonic acid, trichlorobenzenephosphonic acid, trichloromethancphosphinic acid, dibromoethanephosphnic acid.

As noted the new alkali metal-amine halohydrocarbyl phosphonates are particularly useful when used in combination with certain classes of additives as previously defined. One class of additives is a sulfurized and/or sulfohalogenated fatty material such as animal, vegetable and marine fats and oils and derivatives thereof. Materials of this type can be prepared by the methods described in US. Patents 2,322,859; 2,454,034; 2,459,717; 2,467,137; 2,614,078; 2,633,825 and 2,701,237. Among such materials are sulfurized or sulfo-chlorinated fats, fatty oils of the animal, vegetable and marine type and derivatives thereof, such as sulfurized or sulfo-chlorinated tallow, lard, lanolin, jojoba, oil, rapeseed oil, sperm oil, fatty acids of these fats and oils as well as their esters such as G to C saturated and unsaturated fatty acids, e.g. myristic, stearic, oleic acids, polymerized fatty acids such as polymerized linoleic acid or Empol 1022 which is a polymerized fatty acid made by Emery Industries; or esters such as cetyl stearate, cetyl oleate and mixtures thereof; halogenated fats, oils, waxes such as chlorinated paraflin wax, chlorinated tallow, etc. of these materials preferred are the sulfurized and/ or sulfurized-chlorinated sperm oil, lanolin, rapeseed oil, oleic acid, chlorinated paraffin Wax and cetyl olcate as well as mixtures thereof.

The other class of materials is an oilsoluble partial ester of polyhydric alcohol and fatty acid having from 832 carbon atoms, preferably fatty acids having 102() carbon atoms, the preferred esters are those derived from polyhydroxy alcohols having a neocarbon atom such as pentaerythritol or derivatives thereof and C1040 unsaturated fatty acids.

However, the acids which can be used to make the partial esters from any of the above alcohols include aliphatic carboxylic acids; cyclo organic carboxylic acids; aromatic carboxylic acids, sulfonic acids and the like. The aliphatic carboxylic acids include the mono and polycarboxylic acids of from 8 to 32, and preferably from 10 to 20, carbon atoms and include saturated and unsaturated fatty acids of from about 10 to 20 carbon atoms such as lauric, stearic, oleic and linoleic acids, as well as aliphatic polycarboxylic acids such as alkenyl succinic acid, alkyl adipic acid and the like. The cyclic carboxylic acids include naphthenic acids, such as cycloexane carboxylic acid, alkylcyclohexane carboxylic acids, alkylcyclopentane carboxylic acid, abietic acid and the like. The aromatic acids include the substituted aromatic carboxylic acids such as bcnzoic, salicyclic phthalic, anthranilic acids, the alkylrated salicyclic and anthranilic acids in which the alkyl radical is from 3 to 20 carbon atoms being preferred ones.

Specific esters derived from simple alkanepolyols include glycerol nonooleate, glycerol monostearate, glycerol monoricinoleate, pentaerythritol monocaprylate, pentaerythritol monoand dilaurate, pentaerythitol monoand dioleate, pentaerythritol monoand distear-ate, mono-, di-, and triethylene glycol monooleate, propylene glycol monoricinoleate, monoethylone glycol monooleate, triethylene glycol monostearate, sorbitol monolaurate, mannitol monooleate, mannitol dioleate, sorbitol dioleate, etc.

Esters derived from ether-alcohols as described may be prepared by the method described in US. Patent 2,322,- 820. Examples of such esters which must contain at least one and preferably more than one free hy-droxyl group are sorbitan monoand dioleate, sonbit-an mono and dilaurate, mannitan monoand distearate, mannitan monoand dioleate, sorbitan monoand dipalmitate, sorbitan sesquioleate, sorbitan mononaphthenate, mannitan monolaurate, etc.

Esters derived from the sugar alcohols include glucose monoleate, glucose monon'ncinolea'te, sorbose monostearate, frutose monooleate and the like.

The alkali metal-amine hal-ohydrocarbyl phosphonate alone or in combination with additives as defined are each used in amounts ranging from about 0.5% to about 5% by Weight.

Certain viscosity indexes and pour point depressing agents are particularly suited for use in compositions of the present invention. Such materials are meth-acrylate polymers of C alkyl alcohols such as lauryl and/or stearyl methacrylate. Such polymers are commercially available from Rohm and Haas under the trade name of Acryloid 150 or 710. Acryloid 710 is predominantly a copolymer mixture of octyl and lauryl methacrylates having a molecular weight of from about 10,000 to 20,000 or Acryloid 150 which is predominantly a copolymer mixture of cetyl, lauryl and octyl methacrylates having a molecular weight of about 10,00015,000. These polymers are sold commercially as 40% concentrate of the polymer in a mineral lubricating oil base, to provide a viscous liquid having a viscosity at 210 F. of from about 600 to 850 centistokes. On an oil-free basis the polymers when used in compositions of this invention vary from 0.001% to 5%.

Base oils to which additives of this invention are added may be selected froma variety of natural oils such as paraifinic, naphthenic and mixed base mineral oils having 250 SUS at 210 F. In addition, synthetic oils may be used such as polymerized olefins, alkylated aromatics; polyalkyl silicone polymers, e.g., liquid dimethyl silicone polymers, other silicone polymers; H S-adducts of unsaturated ethers and thioethers, e.g., H 8 adduct of diallyl ether; esters, e.-g., di(2-ethylhexyl) sebaeate. Mixtures of natural and synthetic oils can be used.

Specific examples of compositions of this invention are:

Composition A Percent wt. Na-A monoch-loromethylphosphonate 3.0 Sulfurized sperm oil 4.0 Pentaerythritol monooleate 1.0 Methacrylate polymer (Acryloid 150) 0.2 Mineral lubricating oil (100 SSU at 210 F. neut.) 66.25

Bright stock (150 SSU at 210 F.) 25.30

*As described in Table I.

Composition B Net-A trichloromethylphosphon-ate 3.25 Sulfurized sperm oil 4.0 'Pentaerythritol monooleate 1.0 Methacrylate polymer (Acryloid 150) 0.2 Mineral lubricating oil (100 SSU at 210 F. nent.) 66.25 Bright stock (150 SSU at 210 F.) 25.30

Composition C Nat-A monochloromethylphosphonate 5 Sulfurized sperm oil 4 Pentaerythritol monooleate 1 Mineral oil (SAE 90) Balance Composition D Na-A monochloromethylphosphonate 5 Sulfurized-chlorinated sperm oil 4 Pentaerythritol monooleate 1 Mineral oil (SAE Balance Composition E- N-a-A monochloromethylphosphonate 5 Mineral oil (SAE 30) Balance Composition 'F K-A monochloromethylphosphonate 3.25 Sulfurized sperm oil 4.0 Pentaerythritol monooleate 1.0 Methaorylate polymer (Acryloid 150) 0.2 Mineral lubricating oil SSU at 210 F. neut.) 66.25 Bright stock (150 SSU at 210 F.) 25.30

The outstanding properties of compositions of the present invention are evidenced by the results as shown in Table II. The tests are CRC L-37 and L-42 described in SAE Jour., March 1960, page 475-480; 325 F. Ordnance Thermal Stability Test, N. T. Meckel and R. D. Quillian, In, A Study of Gear Lubricant Thermal Oxidative Degradation Phenomena, Soc. of Automotive Engrs, Preprint T-38, presented at the SAE Annual Meeting, Detroit, January 11-15, 1960; Continental Oxidation Test described in Anal. Chem, 20, 547, June 1948, and in the 4 Ball Extreme Pressure Tester operated for 1 minute at 1800 r.p.rn. and room temperature, steel on steel.

3 About 6% tooth are scored. b Composition X same as Composition A except that for the mixed N a.A monochloromethylphosphonate ClOHzP OH.Aa

the full amine (A salt was used; namely ClCHzP OH.A3

where A; is defined in Table 1.

e The value of 9.5 obtained on seven diflerent tests.

d The value of 8 was obtained on four different tests.

Compositions of this invention are applicable for high temperature, pressure and speed use as encountered in automotive and truck engines as well as various industrial equipment.

We claim as our invention:

1. A lubricating oil composition consisting essentially of a major amount of lubricating oil and from about 0.05% to about 5% of an alkali metal-C alkylarnine salt of a halo-substituted C hydrocarbyl phosphonic acid.

2. A lubricating oil composition consisting essentially of a major amount of lubricating oil and from about 0.05% to about 5% of an alkali metal-primary C alkylamine salt of a halo-substituted C alkyl phosphonic acid.

3. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.05 to about 5% of an alkali metal-primary C alkylamine salt of an a-chloro-substituted C alkyl phosphonic acid.

4. A mineral lubricating oil composition consisting essentially ofa major amount of mineral lubricating oil and from about 0.05 to about 5% of Nta-primary C alkylamine salt of chloromethyl phosphonic acid.

5. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.05 to about 5% of a mixed Na-primary PC alkylamine salt of chloromethyl phosphonic acid.

6. A lubricating oil composition consisting essentially of a major amount of lubricating oil and from about 0.05 to about 5% each of (1) an alkali metal-C alkylamine salt of a halo-substituted C hydrooarbyl phosphonic acid, (2) an oil-soluble sulfurized fatty oil and (3) an oil-soluble partial ester of a polyhydric alcohol selected from the group consisting of glycerol and pentaerythritol and an aliphatic carboxylic acid having from 10 to 20 carbon atoms.

7. A lubricating oil composition consisting essentially of a major amount of lubricating oil and from about 0.05 to about 5% each of (1) an alkali metal-primary C alkylamine salt of a halo-substituted C alkyl phosphonic acid, and (2) an oil-soluble sulfurized fatty oil and (3) an oil-soluble partial ester of pentaerythritol and an aliphatic monocarboxylic acid having from to 20 carbon atoms.

8. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.05% to about each of (1) an alkali metal-primary C alkylamine salt of an a-chloro-substituted C alkyl phosphonic acid, (2) an oil-soluble sulfurized fatty oil and (3) an oil-soluble partial ester of pentaerythritol and an aliphatic monocarboxylic acid having from 10 to 20 carbon atoms.

9. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.05% to about 5% each of Na-primary C al'kylamine salt of chloromethyl phosphonic acid, sulfurized spenrn oil and pentaerythritol monooleate.

10. A mineral lubricating oil composition consisting essentially of a major amount of mineral lubricating oil and from about 0.05% to about 5% each of a mixed Naprimary t-C alkylamine salt of chloromethyl phosphonic acid, sulfurized spenm oil and pentaerythritol monooleate.

11. The lubricating composition of claim 10 containing a minor amount of a C alkyl methacrylate polymer.

12. A lubricating oil composition consisting essentially of a major amount of a synthetic ester base oil and from about 0.05% to about 5% of an alkali metal-C alkylamine salt of a halo-substituted C hydrocarbyl phosphonic acid.

13. A lubricating oil composition consisting essentially of a major amount of a synthetic ester base oil and from about 0.05% to about 5% of a mixed N-a'primary t-C alkylamine salt of chloromethyl phosphonic acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,382,043 Farrington et a1 Aug. 14, 1945 2,563,506 Werntz Aug. 7, 1951 2,670,369 Filatoif-Rocq et a1. Feb. 23, 1954 2,674,616 Morris Apr. 6, 1954 2,849,397 Hotten Aug. 26, 1958 2,858,332 Watson et al. Oct. 28, 1958 2,874,120 Watson et al Feb. 17, 1959 2,882,228 Watson et al. Apr. 14, 1959 2,889,282 Lorensen et al. June 2, 959 

1. A LUBRICATING OIL COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF LUBRICATING OIL AND FROM ABOUT 0.05% TO ABOUT 5% OF AN ALKALI METAL-C8-24 ALKYLAMINE SALT OF A HALO-SUBSTITUTED C1-30 HYDROCARBYL PHOSPHONIC ACID. 